<template>
	<transition name="el-zoom-in-top" @after-leave="$emit('dodestroy')">
		<div
			v-show="visible"
			class="el-picker-panel el-date-range-picker el-popper"
			:class="[
				{
					'has-sidebar': $slots.sidebar || shortcuts
				},
				popperClass
			]">
			<div class="el-picker-panel__body-wrapper">
				<slot name="sidebar" class="el-picker-panel__sidebar"></slot>
				<div class="el-picker-panel__sidebar" v-if="shortcuts">
					<button
						type="button"
						class="el-picker-panel__shortcut"
						v-for="(shortcut, key) in shortcuts"
						:key="key"
						@click="handleShortcutClick(shortcut)">
						{{ shortcut.text }}
					</button>
				</div>
				<div class="el-picker-panel__body">
					<div class="el-picker-panel__content el-date-range-picker__content is-left">
						<div class="el-date-range-picker__header">
							<button
								type="button"
								@click="leftPrevYear"
								class="el-picker-panel__icon-btn el-icon-d-arrow-left"></button>
							<button
								type="button"
								v-if="unlinkPanels"
								@click="leftNextYear"
								:disabled="!enableYearArrow"
								:class="{ 'is-disabled': !enableYearArrow }"
								class="el-picker-panel__icon-btn el-icon-d-arrow-right"></button>
							<div>{{ leftLabel }}</div>
						</div>
						<BasicMonthTable
							selection-mode="range"
							:date="leftDate"
							:default-value="defaultValue"
							:min-date="minDate"
							:max-date="maxDate"
							:range-state="rangeState"
							:disabled-date="disabledDate"
							@changerange="handleChangeRange"
							@pick="handleRangePick">
						</BasicMonthTable>
					</div>
					<div class="el-picker-panel__content el-date-range-picker__content is-right">
						<div class="el-date-range-picker__header">
							<button
								type="button"
								v-if="unlinkPanels"
								@click="rightPrevYear"
								:disabled="!enableYearArrow"
								:class="{ 'is-disabled': !enableYearArrow }"
								class="el-picker-panel__icon-btn el-icon-d-arrow-left"></button>
							<button
								type="button"
								@click="rightNextYear"
								class="el-picker-panel__icon-btn el-icon-d-arrow-right"></button>
							<div>{{ rightLabel }}</div>
						</div>
						<BasicMonthTable
							selection-mode="range"
							:date="rightDate"
							:default-value="defaultValue"
							:min-date="minDate"
							:max-date="maxDate"
							:range-state="rangeState"
							:disabled-date="disabledDate"
							@changerange="handleChangeRange"
							@pick="handleRangePick">
						</BasicMonthTable>
					</div>
				</div>
			</div>
		</div>
	</transition>
</template>
<script lang="ts">
export default async function () {
	const [{ isDate, modifyWithTimeString, prevYear, nextYear, nextMonth }, Clickoutside] =
		await _.$importVue([
			"/common/ui-x/components/form/xDatePicker/dateUtils.vue",
			"/common/ui-x/directive/clickoutside.vue"
		]);

	const calcDefaultValue = defaultValue => {
		if (Array.isArray(defaultValue)) {
			return [new Date(defaultValue[0]), new Date(defaultValue[1])];
		} else if (defaultValue) {
			return [new Date(defaultValue), nextMonth(new Date(defaultValue))];
		} else {
			return [new Date(), nextMonth(new Date())];
		}
	};
	return defineComponent({
		directives: { Clickoutside },
		computed: {
			btnDisabled() {
				return !(
					this.minDate &&
					this.maxDate &&
					!this.selecting &&
					this.isValidValue([this.minDate, this.maxDate])
				);
			},

			leftLabel() {
				return this.leftDate.getFullYear() + " " + this.i18n("el.datepicker.year");
			},

			rightLabel() {
				return this.rightDate.getFullYear() + " " + this.i18n("el.datepicker.year");
			},

			leftYear() {
				return this.leftDate.getFullYear();
			},

			rightYear() {
				return this.rightDate.getFullYear() === this.leftDate.getFullYear()
					? this.leftDate.getFullYear() + 1
					: this.rightDate.getFullYear();
			},

			enableYearArrow() {
				return this.unlinkPanels && this.rightYear > this.leftYear + 1;
			}
		},

		data() {
			return {
				popperClass: "",
				value: [],
				defaultValue: null,
				defaultTime: null,
				minDate: "",
				maxDate: "",
				leftDate: new Date(),
				rightDate: nextYear(new Date()),
				rangeState: {
					endDate: null,
					selecting: false,
					row: null,
					column: null
				},
				shortcuts: "",
				visible: "",
				disabledDate: "",
				format: "",
				arrowControl: false,
				unlinkPanels: false
			};
		},

		watch: {
			value(newVal) {
				if (!newVal) {
					this.minDate = null;
					this.maxDate = null;
				} else if (Array.isArray(newVal)) {
					this.minDate = isDate(newVal[0]) ? new Date(newVal[0]) : null;
					this.maxDate = isDate(newVal[1]) ? new Date(newVal[1]) : null;
					if (this.minDate) {
						this.leftDate = this.minDate;
						if (this.unlinkPanels && this.maxDate) {
							const minDateYear = this.minDate.getFullYear();
							const maxDateYear = this.maxDate.getFullYear();
							this.rightDate =
								minDateYear === maxDateYear ? nextYear(this.maxDate) : this.maxDate;
						} else {
							this.rightDate = nextYear(this.leftDate);
						}
					} else {
						this.leftDate = calcDefaultValue(this.defaultValue)[0];
						this.rightDate = nextYear(this.leftDate);
					}
				}
			},

			defaultValue(val) {
				if (!Array.isArray(this.value)) {
					const [left, right] = calcDefaultValue(val);
					this.leftDate = left;
					this.rightDate =
						val &&
						val[1] &&
						left.getFullYear() !== right.getFullYear() &&
						this.unlinkPanels
							? right
							: nextYear(this.leftDate);
				}
			}
		},

		methods: {
			handleClear() {
				this.minDate = null;
				this.maxDate = null;
				this.leftDate = calcDefaultValue(this.defaultValue)[0];
				this.rightDate = nextYear(this.leftDate);
				this.$emit("pick", null);
			},

			handleChangeRange(val) {
				this.minDate = val.minDate;
				this.maxDate = val.maxDate;
				this.rangeState = val.rangeState;
			},

			handleRangePick(val, close = true) {
				const defaultTime = this.defaultTime || [];
				const minDate = modifyWithTimeString(val.minDate, defaultTime[0]);
				const maxDate = modifyWithTimeString(val.maxDate, defaultTime[1]);
				if (this.maxDate === maxDate && this.minDate === minDate) {
					return;
				}
				this.onPick && this.onPick(val);
				this.maxDate = maxDate;
				this.minDate = minDate;

				// workaround for https://github.com/ElemeFE/element/issues/7539, should remove this block when we don't have to care about Chromium 55 - 57
				setTimeout(() => {
					this.maxDate = maxDate;
					this.minDate = minDate;
				}, 10);
				if (!close) return;
				this.handleConfirm();
			},

			handleShortcutClick(shortcut) {
				if (shortcut.onClick) {
					shortcut.onClick(this);
				}
			},

			// leftPrev*, rightNext* need to take care of `unlinkPanels`
			leftPrevYear() {
				this.leftDate = prevYear(this.leftDate);
				if (!this.unlinkPanels) {
					this.rightDate = prevYear(this.rightDate);
				}
			},

			rightNextYear() {
				if (!this.unlinkPanels) {
					this.leftDate = nextYear(this.leftDate);
				}
				this.rightDate = nextYear(this.rightDate);
			},

			// leftNext*, rightPrev* are called when `unlinkPanels` is true
			leftNextYear() {
				this.leftDate = nextYear(this.leftDate);
			},

			rightPrevYear() {
				this.rightDate = prevYear(this.rightDate);
			},

			handleConfirm(visible = false) {
				if (this.isValidValue([this.minDate, this.maxDate])) {
					this.$emit("pick", [this.minDate, this.maxDate], visible);
				}
			},

			isValidValue(value) {
				return (
					Array.isArray(value) &&
					value &&
					value[0] &&
					value[1] &&
					isDate(value[0]) &&
					isDate(value[1]) &&
					value[0].getTime() <= value[1].getTime() &&
					(typeof this.disabledDate === "function"
						? !this.disabledDate(value[0]) && !this.disabledDate(value[1])
						: true)
				);
			},

			resetView() {
				// NOTE: this is a hack to reset {min, max}Date on picker open.
				// TODO: correct way of doing so is to refactor {min, max}Date to be dependent on value and internal selection state
				//       an alternative would be resetView whenever picker becomes visible, should also investigate date-panel's resetView
				this.minDate = this.value && isDate(this.value[0]) ? new Date(this.value[0]) : null;
				this.maxDate = this.value && isDate(this.value[0]) ? new Date(this.value[1]) : null;
			}
		},

		components: {
			BasicMonthTable: () =>
				_.$importVue("/common/ui-x/components/form/xDatePicker/basic/BasicMonthTable.vue")
		}
	});
}
</script>
